Coexistence of superconductivity and antiferromagnetism in (Li0.8Fe0.2)OHFeSe
Coexistence of superconductivity and antiferromagnetism in (Li0.8Fe0.2)OHFeSe
复制标题
(Li0.8Fe0.2)OHFeSe中超导性与反铁磁性的共存
DOI：
10.1038/nmat4155
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发表时间：
2015-03-01
期刊：
影响因子：
41.2
通讯作者：
Chen, X. H.
中科院分区：
文献类型：
--
作者：
Lu, X. F.;Wang, N. Z.;Chen, X. H.
硒化铁超导体表现出许多独特的特性，有助于更广泛地理解高t -c铁基超导体的超导机制。然而，在A(x)Fe(2)Se(2) （A = K, Rb, Cs）的情况下，交错生长的反铁磁绝缘相的存在使得底层物理的研究存在问题。此外，插入碱金属离子、NH3分子或有机分子的基于fese的体系对空气极其敏感，这阻碍了对其物理性质的进一步研究。因此，需要找到一种稳定且易于获取的基于fese的超导体来详细研究其物理性质。在这里，我们报道了一种空气稳定材料（Li0.8Fe0.2） OHFeSe的合成，该材料在接近40 K的温度下仍保持超导性。通过x射线和中子粉末衍射以及核磁共振的结合，可以明确地确定晶体结构。此外，反铁磁有序与超导性共存。该合成路线为探索其他相关体系的超导性开辟了道路，并证实了硒化铁作为更广泛地理解铁衍生物超导性的平台的吸引力。
Iron selenide superconductors exhibit a number of unique characteristics that are helpful for understanding the mechanism of superconductivity in high-T-c iron-based superconductors more generally. However, in the case of A(x)Fe(2)Se(2) (A = K, Rb, Cs), the presence of an intergrown antiferromagnetic insulating phase makes the study of the underlying physics problematic. Moreover, FeSe-based systems intercalated with alkali metal ions, NH3 molecules or organic molecules are extremely sensitive to air, which prevents the further investigation of their physical properties. It is therefore desirable to find a stable and easily accessible FeSe-based superconductor to study its physical properties in detail. Here, we report the synthesis of an air-stable material, (Li0.8Fe0.2) OHFeSe, which remains superconducting at temperatures up to similar to 40 K, by means of a novel hydrothermal method. The crystal structure is unambiguously determined by a combination of X-ray and neutron powder diffraction and nuclear magnetic resonance. Moreover, antiferromagnetic order is shown to coexist with superconductivity. This synthetic route opens a path for exploring superconductivity in other related systems, and confirms the appeal of iron selenides as a platform for understanding superconductivity in iron pnictides more broadly.